feat: slskd reconnect guard in downloaders_reset, mass v2 sync

- downloaders_reset: connection check block before slskd API sections;
  triggers PUT /api/v0/server reconnect if disconnected, polls 60s,
  gates Stuck Searches and Dead Transfer Records on SLSKD_CONNECTED
- Sync all modified/new/deleted files from v2 refactor across Docker_Essentials,
  Media, Monitors, Partnership, Rsync, Tools, Transcodes, unRAID_Essentials,
  common.sh, master confs, and new Manual/README docs

Tools/fallback_state_reset.sh

@@ -2,46 +2,66 @@
 # ==============================================================================================
 # ============================= Failover State Reset ===========================================
 # ==============================================================================================
-# Resets the fallback state file to NORMAL and clears all tier flags.
-# Use when the fallback state file is stuck in a non-NORMAL state after:
-#   - Failover testing that left state as FALLBACK
-#   - A failed handback that did not complete cleanly
-#   - Manual intervention that left state inconsistent
-#   - fallback.sh was killed mid-cycle and state is unknown
 #
-# ── WHAT THIS DOES ────────────────────────────────────────────────────────────────────────────
+# PURPOSE
+# ─────────────────────────────────────────────────────────────────────────────
+# Resets the fallback state file to NORMAL and clears all tier flags. Use when
+# the state file is stuck after failover testing, a failed handback, manual
+# intervention, or fallback.sh being killed mid-cycle.
+#
 # Writes a fresh state file with:
-#   state=NORMAL
-#   fallback_start=0
-#   handback_strikes=0
+#   state=NORMAL / fallback_start=0 / handback_strikes=0
 #   tier2_started=false / tier3_started=false / tier4_started=false
 #
-# Does NOT start or stop any containers — state file only.
-# After reset, fallback.sh will resume from NORMAL on its next cycle.
+# Does NOT start or stop containers — state file only. After reset, fallback.sh
+# resumes from NORMAL on its next cycle.
 #
-# ── ⚠️  ONLY RUN WHEN SAFE ────────────────────────────────────────────────────────────────────
-# Verify BEFORE resetting:
-#   ✓ Right containers running on the right server
-#   ✓ DDNS pointing at the correct server
-#   ✓ No active failover actually in progress
-#   ✓ Both servers can see each other
+# WARNING: Only run when you have verified the stack is actually in a normal
+# state — right containers on the right server, DDNS correct, no active failover
+# in progress. Resetting state during a real failover causes fallback.sh to stop
+# covering the remote server until the next detection cycle.
 #
-# Resetting state while a real fallback is happening causes fallback.sh to stop
-# covering the remote server — services go offline until next detection cycle.
+# ==============================================================================================
+# OPERATIONAL SAFEGUARDS
+# ==============================================================================================
 #
-# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
-#   fallback.sh running check  — warns if fallback.sh is active when reset is attempted
-#   acquire_lock               — prevents concurrent resets
-#   flock on state write       — prevents race with fallback.sh mid-cycle read
-#   Confirmation required      — interactive: type YES | non-interactive: --force flag
-#   validate_unraid_cmd        — notify validated before use
+# Active Fallback Detection
+#   Checks whether fallback.sh is currently running and warns if so. A reset
+#   during an active cycle causes fallback.sh to lose its state on the next read.
+#
+# Single Instance Lock
+#   acquire_lock prevents concurrent resets.
+#
+# flock on State Write
+#   The state file write is protected with flock — prevents a race condition
+#   with fallback.sh reading the file mid-cycle.
+#
+# Confirmation Required
+#   Interactive mode prompts for YES before writing. Use --force to bypass in
+#   non-interactive contexts (cron, scripts).
+#
+# Notification Validated
+#   validate_unraid_cmd confirms the notify script is present before use.
+#
+# ==============================================================================================
+# RUNTIME MODES
+# ==============================================================================================
+#
+# fallback_state_reset.sh
+#     Show current state and prompt for YES before resetting.
+#
+# fallback_state_reset.sh --dry-run
+#     Show current state and what the new state file would contain. No write.
+#
+# fallback_state_reset.sh --status
+#     Show current state file contents and exit.
+#
+# fallback_state_reset.sh --force
+#     Reset without interactive confirmation. Safe for scripted use.
+#
+# fallback_state_reset.sh --force --dry-run
+#     Dry run without the confirmation prompt.
 #
-# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
-#   fallback_state_reset.sh                    — interactive reset (prompts for YES)
-#   fallback_state_reset.sh --dry-run          — show current state, show what would be written
-#   fallback_state_reset.sh --status           — show current state file contents and exit
-#   fallback_state_reset.sh --force            — non-interactive reset (no prompt, use in scripts)
-#   fallback_state_reset.sh --force --dry-run  — dry run without prompt
 # ==============================================================================================
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"